Model Number 304-20Event Date 09/09/2014Event Type Malfunction Manufacturer Narrative Manufacturer device history records were reviewed. Review of the lead device history records confirmed all quality tests were passed prior to distribution. Device failure is suspected, but did not causer or contribute to a death or serious injury.

Event Description It was reported that the patient had generator and lead replacement surgery on (b)(6) 2014. The explanted devices were returned to the manufacturer for analysis. However, analysis has not been completed to date.

Event Description A/p and lateral neck images and a/p back x-ray images were reviewed by the manufacturer. The generator is implanted on the patient's back due to a history of playing with the device. The connector pin does not appear to be fully inserted inside the connector block. However, it is unable to be confirmed whether the pin is fully inserted into the generator header due to the angle of the images. There does not appear to be any lead discontinuities or sharp angles in the lead portion that was able to be visualized; however, the presence of a fracture cannot be ruled out due to the quality of the images. Based on the x-ray images provided, the root cause of the high impedance is unclear. However, the high impedance may possibly be related to incomplete lead pin insertion into the generator header. Additionally, the presence of a micro-fracture in the lead cannot be ruled out. There is a portion of the lead located behind the generator that could not be assessed.

Manufacturer Narrative Only a portion of the lead was returned for analysis which did not reveal any anomalies. Device failure is suspected in the lead portion not returned, but did not cause or contribute to a death or serious injury.

Event Description Analysis of the lead and generator was completed. Note that a portion of the lead assembly (body) including the electrodes was not returned for analysis; therefore a complete evaluation could not be performed on the entire lead product. The condition of the returned lead portion is consistent with conditions that typically exist following an explant procedure. No obvious anomalies were noted. The setscrew marks found on the lead connector pin provide evidence that, at one point in time, a good mechanical and electrical connection was present. Continuity checks of the returned lead portion were performed, during the visual analysis, and no discontinuities were identified. Based on the findings in the lab, there is no evidence to suggest a discontinuity in the returned portion of the device which may have contributed to high lead impedance. There were no adverse functional, mechanical, or visual issues identified with the returned generator. Review of the internal generator data revealed that a 25% change in impedance occurred on (b)(6) 2014 from 2605 ohms to >10000 ohms.

Event Description It was reported that high lead impedance was detected on the patient¿s vns system on (b)(4) 2014. The device was programmed off to 0ma. The patient was referred for x-rays and for replacement surgery. The nurse reported that the x-rays showed intact leads. There was no history of trauma or manipulation reported. The generator is implanted on the patient's back due to a history of playing with the device. The patient cannot reach the device due to it previously being implanted on his back. Surgical intervention is likely but has not occurred to date.

Event Date 10/30/2014Event Type Malfunction Manufacturer Narrative Manufacturer reviewed x-rays of implanted device. X-rays reviewed by manufacturer, no gross lead discontinuities visualized. Device failure is suspected, but did not cause or contribute to a death or serious injury.

Manufacturer Narrative Describe event or problem; corrected data: the previously submitted mdr inadvertently stated that the electrodes were in correct arrangement when actually the arrangement of the electrodes could not be assessed.

Event Description The arrangement of the electrodes could not be assessed. Additional information was received stating that the vns patient¿s device should lead impedance within normal limits (impedance value ¿ 2543 ohms) during an office visit prior to generator replacement on (b)(6) 2014. Patient manipulation or trauma is not believed to have caused or contributed to the high impedance. The patient¿s device was disabled following the high impedance observation.

Event Description It was reported that during generator replacement surgery due to end of service, the vns patient¿s replacement generator was connected with the existing lead and diagnostic results revealed high impedance. The surgeon reinserted the lead pin and subsequent tests showed lead impedance within normal limits. The procedure was completed but the patient device was tested again during recovery and high impedance was again observed. No tests could be performed prior to the procedure due to end of service condition. X-rays were provided to the manufacturer for further review. The generator appears in the left chest in a normal placement. The filter feed-through wires appear to be intact. The lead connector pin appears fully inserted into the generator connector block. The electrodes appeared to be placed in normal arrangement. Portions of the lead were unable to be assessed due to the quality of the images provided. Part of the lead was behind the generator and could not be assessed. No clear lead breaks or sharp angles were found in the parts of the lead that could be assessed. Based on the images provided, the cause of the high lead impedance remains unknown. No known surgical interventions for the high impedance have occurred to date.

Event Description It was reported that lead revision surgery was planned. It was later confirmed that the intervention was completed on 02/05/2015. The explanted lead has not been returned to date.

Event Description It was reported that a patient's device was showing high impedance. The patient was recently implanted with an impedance with ok impedance. It was further noted that the patient was experiencing an increase in seizures. X-rays were received but could not properly assess complete pin insertion or fracture due to image quality. An update was received that impedance was back within normal limits. No intervention was planned to date. It was noted that testing could not be performed with the patient at different conditions due to the patient's condition. Internal investigation identified that a change in the timing of the impedance test may result in higher impedances for model 1000 generator compared to those reported by model 103-106 generator. As indicated in the physician's manual, high lead impedance (>/= 5300 ohms), in the absence of other device-related complications, is not an indication of a lead or generator malfunction. No relevant surgical intervention has occurred to date. At the time of this report it is unclear whether this event is related to this "m1000 higher impedances" issue mentioned above. No additional relevant information was received to date.

Model Number 302-20Event Date 01/19/2015Event Type Malfunction Event Description It was reported that the vns patient¿s device was tested during an office visit on (b)(6) 2015 and system diagnostic results revealed high impedance (dcdc ¿ 7). Patient manipulation or trauma is not believed to have caused or contributed to the high impedance. X-rays were provided to the manufacturer for further review. The generator appears in the left chest in a normal placement. The filter feed-through wires, the lead connector pin, and large portions of the lead could not be assessed due to the poor quality of the images provided. Part of the lead was behind the generator and could not be assessed. No clear lead breaks or sharp angles were found in the parts of the lead that could be assessed. No known surgical interventions have occurred to date.

Manufacturer Narrative Manufacturer reviewed x-rays of implanted device. X-rays reviewed by manufacturer, no gross lead discontinuities visualized. Device failure is suspected, but did not cause or contribute to a death or serious injury.

Event Description Additional information was received stating that the vns patient underwent generator and lead replacement surgery on (b)(6) 2015. The explanted devices have not been returned to date.

Event Description It was reported that the recently implanted vns patient¿s device showed high impedance. Patient manipulation or trauma is not believed to have caused or contributed to the high impedance. X-rays were provided to the manufacturer for review. The generator appears in the left chest in a normal placement. The filter feed-through wires appear to be intact. The lead connector pin could not be confirmed to be fully inserted into the generator connector block due to the low quality of the images provided. Part of the lead was behind the generator and could not be assessed. No clear lead breaks or sharp angles were found in the parts of the lead that could be assessed. It was noted that the patient¿s device was tested during implant surgery and showed lead impedance within normal limits. The patient was referred for surgery but no known surgical interventions have occurred to date.

Model Number 302-20Event Date 01/27/2015Event Type Malfunction Event Description Abraded openings were observed on the inner silicone tubes in one area of the lead, and the quadfilar coils appeared to be exposed and touching, in some areas.

Manufacturer Narrative Device failure occurred, but did not cause or contribute to a death.

Manufacturer Narrative Manufacturer reviewed x-ray image of implanted device. X-ray image reviewed by the manufacturer, no gross lead discontinuities visualized. Device failure is suspected, but did not cause or contribute to a death.

Event Description It was reported that high impedance warning message was received upon programming the patent¿s device. They device was tested again with the device programmed off, and diagnostics were reportedly fine. After the mri was completed and the patient was turned back on, system and normal mode diagnostics resulted in high impedance. An ap chest x-ray image was received for review. The generator appears normally placed on the left chest. The connector pin insertion into the connector block cannot be properly assessed. Some of the lead is not visible at the generator site, and appears to be partially behind the generator. Due to the limited x-rays taken and image quality, the electrodes and strain relief are unable to be assessed. Based on the image seen, the cause of the high impedance was unable to be determined. The lead continuity cannot be assessed and discontinuity on the lead or at the generator cannot be properly visualized. No assessment can be made on the portion of the lead that is not visible. The patient's device was programmed off due to the high impedance. The nurse reports that the patient has drop attacks and thinks the patient fell during a seizure most likely damaging the system. The patient has been experienced increased seizures recently. No known trauma or manipulation has occurred. The patient had generator and lead replacement surgery on (b)(6) 2015. The explanted products have not been received to date. Good faith attempts for additional relevant information have been unsuccessful to date.

Event Description An analysis was performed on the returned lead portions and generator. During the visual analysis of the lead, quadfilar coil 1 appeared to be broken. Scanning electron microscopy was performed and identified the area as being mechanically damaged which prevented identification of the coil fracture type and no pitting. It is unknown if the breaks occurred while stimulation was present due to the absence of metal pitting on the broken coil wire surfaces. With the exception of the observed discontinuity, the condition of the returned lead portions is consistent with conditions that typically exist following an explant procedure. No other obvious anomalies were noted. The setscrew marks found on the lead connector pin provide evidence that, at one point in time, a good mechanical and electrical connection was present. Continuity checks of the returned lead portions were performed, during the visual analysis, and no other discontinuities were identified. Based on the findings in the product analysis lab, there is evidence to suggest a discontinuity in the returned portions of the device which may have contributed to reported events. Note that since the electrode array section was not returned for analysis, an evaluation and resulting commentary cannot be made on that portion of the lead. A comprehensive automated electrical evaluation showed that the pulse generator performed according to functional specifications. There were no performance or any other type of adverse conditions found with the pulse generator. Review of the generator internal data revealed that a >25% change in impedance occurred on 01/27/2015 from 2028 ohms to 9674 ohms (high impedance).

Event Description The explanted generator and lead were received by the manufacturer for analysis. However, the analysis has not been completed to date.

Model Number 302-20Event Date 03/16/2015Event Type Malfunction Event Description Additional information was received that the patient's generator was not disabled following the high impedance observation, as there were no reported side effects or pain associated with the high impedance tests. It was confirmed that high impedance was not seen during generator implant. Review of manufacturing records confirmed that the generator and lead passed all functional tests prior to distribution. No known surgical interventions have occurred to date.

Manufacturer Narrative Manufacturer reviewed x-rays of implanted device. X-rays reviewed by manufacturer, assessment of the lead could not be performed due to the low resolution of the images provided. Device failure is suspected, but did not cause or contribute to a death or serious injury.

Event Description It was reported that the vns patient¿s device was tested and both normal mode and system diagnostic results revealed high impedance. Patient manipulation or trauma is not believed to have caused or contributed to the high impedance. Lead impedance was within normal limits at the patient¿s last generator replacement on (b)(6) 2014; the lead pin was completely inserted into the generator header and the lead was not damaged during the procedure. X-rays were provided to the manufacturer for review. The generator appears in the left chest in a normal placement. The filter feed-through wires, lead pin insertion, and lead continuity could not be assessed due to the low resolution of the images provided. No known surgical interventions have occurred to date.

Model Number 302-20Event Date 04/14/2015Event Type Malfunction Manufacturer Narrative Manufacturer reviewed x-rays of implanted device. Device manufacturing records and available programming and diagnostic history were reviewed. Review of manufacturing records confirmed that the lead passed all functional tests prior to distribution. X-rays reviewed by manufacturer, no gross lead discontinuities visualized. Device failure is suspected, but did not cause or contribute to a death.

Event Description It was reported that the vns patient had presented with increased seizures and painful stimulation. System diagnostics were run on the vns system on (b)(6) 2015 and they returned a dcdc code 0. Normal mode diagnostics were run on the vns system on (b)(6) 2015 and they returned a dcdc code 0. The pulse generator was disabled. Review of manufacturing records confirmed that the lead passed all functional tests prior to distribution. A battery life estimation for the implanted generator returned 0 years expected until near end of service. Programming history data was reviewed though (b)(6) 2012. The device was last programmed to a 16% duty cycle. The last parameters recorded were 2 ma/30hz/500usec/30sec/3min, magnet mode 2. 25ma/60sec/500usec. Diagnostic history data revealed that system diagnostics recorded on (b)(6) 2012 returned a lead impedance result within normal ranges. Normal mode diagnostics were run on (b)(6)2012 recorded on (b)(6) 2012 returned a lead impedance result within normal ranges. Magnet mode diagnostics recorded on (b)(6) 2012 returned a lead impedance result within normal ranges. Further information was received indicating that the patient had presented pain at the generator implant site. It was also indicated that the patient had undergone a generator replacement the previous year. X-rays were taken and reviewed at the healthcare facility. It was reported that review by the healthcare professional had not found any lead break or disconnection of the lead. Review of the x-showed that the generator appears in the upper left chest in a normal placement. The filter feed-through wires appeared to be intact. The lead connector pin seemed to be fully inserted into the generator connector block. The electrodes appeared normally placed on the vagus nerve. It is difficult to assess if the strain relief bend and loop were used. The tie downs were used but it is unclear, if those were used as indicated in the labeling, due to the picture quality. Part of the lead was behind the generator. No sharp angles or lead breaks were visible on the assessed lead parts. Based on the x-rays, the cause of the reported low impedance remains unknown. Further information was received stating that the seizure frequency was above the pre-vns seizure rate, with complex partial and tonic-clonic seizures. No manipulation of the vns system was suspected. The patient had undergone battery replacement in (b)(6) 2014. On (b)(6) 2015 system diagnostics returned a dcdc code 0, low impedance result. The patient presented mild painful stimulation with a strange sensation near the generator. No known surgical interventions have occurred to date.

Model Number 302-20Event Date 03/30/2015Event Type Malfunction Event DescriptionIt was reported that the vns patient¿s device was tested during an office visit on (b)(6) 2015 and diagnostic results revealed high impedance (impedance value >= 10,000 ohms). X-rays were provided to the manufacturer for review. The generator appears in the left chest in a normal placement. The filter feed-through wires appear to be intact. Due to poor quality of the images provided, continuity of the lead could not be assessed. The patient underwent generator and lead replacement surgery on (b)(6) 2015 due to lead discontinuity. The explanted generator and lead have been returned to the manufacturer where analysis is currently underway.

Manufacturer NarrativeDevice failure caused event, but did not cause or contribute to a death or serious injury.

Event DescriptionAnalysis for the generator was completed. Review of the generator data revealed that there was a >25% change in impedance value on (b)(6) 2015 from 4127 ohms to >10000 ohms. There were no performance issues or any other type of adverse conditions found with the pulse generator. Analysis was completed on the returned lead portions and several abraded openings were observed on the outer silicone tubing. One of the quadfilar coils was broken approximately 2mm from the end of the electrode bifurcation. Scanning electron microscopy (sem) was performed and identified the area as being mechanically damaged. Flat spots and pitting were observed on the coil surface. It is believed that stimulation was present for a certain period of time as evidenced by the presence of metal pitting. Sem analysis of the coil shows characteristics of a lead discontinuity. The abraded openings found on the outer silicone tubing, most likely provided the leakage path for what appeared to have once been body fluids inside the outer silicone tubing. No other anomalies were noted. The setscrew marks found on the lead connector pin provide evidence that, at one point in time, a good mechanical and electrical connection was present. Since the electrode array section was not returned for analysis, an evaluation cannot be made on that portion of the lead.

Manufacturer NarrativeManufacturer reviewed x-rays of implanted device. X-rays reviewed by manufacturer, continuity in the lead could not be assessed with the images provided. Device failure is suspected, but did not cause or contribute to a death or serious injury.

Model Number 304-20Device Problems Fracture; High impedance Event Date 07/19/2015Event Type Malfunction Event Description Product analysis was completed on the returned lead. During the visual analysis several areas of the outer silicone tubing appeared to be compressed and twisted. The positive and negative quadfilar coils were observed to be broken in several places. The coil breaks showed signs of wear, pitting, mechanical damage, and stress induced fracture (including rotational forces). It is believed that stimulation was present for a certain period of time as evidenced by the presence of metal pitting. Abrasions were noted on both the inner and outer silicone tubing. The compressed and twisted conditions observed in the quadfilar coil break areas of the lead tubing suggest the two issues may be related to one another. With the exception of the observed discontinuities and twisted/compressed lead tubing, the condition of the returned lead portions is consistent with conditions that typically exist following an explant procedure. No other obvious anomalies were noted. The setscrew marks found on the lead connector pin provide evidence that, at one point in time, a good mechanical and electrical connection was present. Note that since a portion of the (+) white and (-) green electrode inner silicone tubes and quadfilar coils including the anchor tether and (+) white electrode were not returned, an evaluation and resulting commentary cannot be made on that portion of the lead.

Event Description An international distributor reported that a device was exhibiting high lead impedance via system diagnostics. The physician elected to turn the device off. X-rays were provided to the manufacturer for review. X-ray evaluation found that the generator placement appeared normal in the left upper chest area and the feedthru wires appear to be intact. A gross lead fracture was observed possibly near the clavicle with severe twisting of the lead coil(s)below the clavicle and above the pulse generator. The lead pin appeared to be inserted just past the connector block but due to the angle of the pulse generator and the image quality it could not be conclusively assessed. The physician stated that the patient's convulsions may be responsible for the lead fracture. The patient's generator and lead were explanted and replaced. The explanted generator and lead have been returned to the manufacturer and are currently undergoing product analysis.

Event Description Corrected data: it was reported that the pulse generator was replaced prophylactically and the battery had not reached its ifi point. New information: it was reported that when reviewing x-rays before the surgical revision to those taken after the initial implant, the direction of the generator was different. From this the physician concluded that external factors (the patient's convulsions) led to both the generator migration and the lead fracture. It was reported that the explanted lead was strongly pulled and twisted by the generator due to the patient's convulsions. It was reported that the physician used non-absorbable sutures during the initial implant procedure. Product analysis of the returned pulse generator showed that there were no performance or any other type of adverse conditions found with the generator. Review of the ram/flash data downloaded from the generator shows an indication of increased impedance from 7738 ohms to 11550 ohms on (b)(6) 2015. During product testing various electrical loads were attached to the generator and results of diagnostic tests demonstrate that accurate resistance measurements were obtained in all instances. A comprehensive automated electrical evaluation showed that the pulse generator performed according to functional specifications with an ifi = no condition. The returned lead remains under product analysis.

Event Description It was reported that a patient's m1000 device was showing high impedance at the patient's second visit following implantation surgery. Device history records were reviewed and the device passed all quality tests prior to distribution. X-rays were received. Per the x-rays, the generator placement appeared to be normal in the left axillary chest area. Complete lead pin insertion could not be assessed due to the angle and quality of the images provided. The feed-through wires appeared normal. The lead was observed in the neck and chest. Note that a portion of lead was routed behind the generator and so could not be assessed. The strain relief loop was present per labeling, however no strain relief bend was observed. One tie down was used to secure the strain relief. In the portions of the lead visible, no gross lead fractures or other anomalies were observed. Based on the images provided, no obvious cause for the high impedance was identified. Note that the presence of problems in obscured portions of the lead and microfractures cannot be ruled out. Internal investigation identified that a change in the timing of the impedance test may result in higher impedances for model 1000 generator compared to those reported by model 103-106 generator. As indicated in the physician¿s manual, high lead impedance (">/"=5300 ohms), in the absence of other device-related complications, is not an indication of a lead or generator malfunction. Existing recommendations, as described in the physician¿s manual, should still be followed. Additional investigation is underway.

Model Number 302-20Device Problem High impedance Event Date 01/09/2019Event Type Malfunction Event Description It was reported that the patient was seen again after a lead pin reinsertion surgery, and high impedance was observed. Diagnostics further noted that the output current was not delivering and the patient was complaining of a shocking sensation to her neck. The patient was sent for x-rays and was to be referred for possible lead revision surgery. Clinic notes from the office visit were received and reviewed. It was stated that since the patient's last visit, the patient was experiencing an intermittent "shocking" sensation at the left side of the neck, coughing more, and had chocked while eating three times, one of which became cyanotic and required a heimlich maneuver. The noted diagnostics confirmed the high impedance and low output current delivered that was reported. It was stated that x-rays of the chest and neck showed no apparent lead break. Settings were decreased for the adverse event of painful stimulation, coughing, and choking. Ap and lateral chest and neck x-rays were received for review. The generator placement appeared to be normal in the left axillary chest area. Due to the quality and angle of the images provided, complete lead pin insertion and feed-through wire integrity could not be assessed. The lead was observed in the patient¿s neck appeared to be routed toward the patient¿s left chest. Due to the quality and angle of the image, strain relief and integrity of the lead could not be assessed. A portion of the lead is routed behind the generator. Based on the images provided, no obvious cause of the adverse events or high impedance was identified. Note that the presence of a gross fracture in the portion of the lead excluded from the images or a micro-fracture along the lead body cannot be ruled out. Revision surgery occurred and it was noted that the explanted product was not expected to be returned for analysis as the hospital discards products after surgery. It was specified that only the lead was revised, with the replacement lead placed on the left vagal nerve. Pin reinsertion was not tested. No device was received to date. No additional relevant information was received to date.

Model Number 302-20Event Date 10/22/2013Event Type Malfunction Event Description It was reported that during a follow-up visit high impedance was observed during an office visit. The device was then programmed to 1ma. It was reported that there is no known history of patient manipulation or trauma that would have contributed to the high impedance. An x-ray was received by the manufacturer. During review it was noted that in the portion of the lead that could be visualized there did not appear to be any obvious lead discontinuities. However it was noted that a large portion of the lead could not visualized. Therefore it could not be determined if strain relief was present per labeling. Additionally, due to the quality of the image and the angle of the generator it could not be determined if the lead pin was fully inserted. The presence of a micro-fracture in the lead cannot be ruled out. The physician was unsure if a vns lead and generator replacement would be pursued since the patient was a possible candidate for resective surgery. Lead and generator replacement surgery is not known to have occurred to date.

Model Number 302-20Device Problem Adverse Event Without Identified Device or Use Problem Event Date 10/04/2015Event Type Malfunction Event Description It was reported that vns device diagnostics resulted in high impedance (dcdc converter 7). It was reported that the patient experienced an increase in seizures. It was reported that the device was turned off on (b)(6) 2015. X-rays were taken but not provided to the manufacturer to date for assessment. Review of manufacturing records confirmed that both, the generator and the lead passed all functional tests prior to distribution. Further information was later received indicating that the patient underwent full replacement surgery on (b)(6) 2015. It was reported that device diagnostics with the new lead and generator were within normal limits. The explanted devices were not returned to the manufacturer for analysis.

Event Description X-rays were provided to the manufacturer for review. The generator appears on the x-rays to be placed in upper chest in normal arrangement. The pin connector appears to be not fully inserted. But due to the quality and angle of the provided images, this could not be confirmed. The electrodes appeared to be placed in abnormal arrangement. The upper of the electrode was implanted very low in the neck, not as specified in labeling. Strain-relief bend and loop seemed to have been used. One tie-down was found holding the lead but it's unable to assess if they are placed as specified in labeling. A portion of lead behind the generator could not be assessed. No suspected lead break was found on the visible part of the lead. Further information received confirmed that the lead was implanted very low in the neck, as found on the provided x-rays, because as indicated by the surgeon: "this is his surgical technique".

Event Date 11/03/2015Event Type Malfunction Event Description It was reported that high impedance (dc dc code - 7) was observed on vns patient's system. The device was then disabled. No patient adverse events were reported. X-rays were taken and sent to the manufacturer for review. The generator appears to be placed in the middle of the chest not as recommended in our labeling. The pin connector appears to be fully inserted. The electrodes appeared to be placed in abnormal arrangement: seems to be implanted too low in the neck, in the upper chest. It's unable to assess if a strain relief or loop were used, due to the quality of the provided x-rays. One tie-down was found holding the lead but not as specified by labeling. There is a large portion of the lead coiled around the electrode, which is unable to be assessed. There is no lead behind the generator. No clear lead breaks or sharp bends were found in the visible parts. A micro-fracture could not be ruled out. No known surgical interventions have been performed to date. No additional relevant information has been received to date.

Model Number 304-20Device Problem Adverse Event Without Identified Device or Use Problem Event Date 09/01/2015Event Type Malfunction Event Description It was reported that a patient was experiencing pain around the generator site. Vns output current was decreased from 1. 25 ma to 1. 00 ma to make it more comfortable. Diagnostics were within normal limits and x-rays were reported as unremarkable. No known trauma to the generator site was suspected. X-rays were received and reviewed. The generator placement appeared normal in the left upper chest area and the feedthru wires appear to be intact. The lead pin does not appear to be inserted completely past the connector block but due to the angle of the pulse generator and the image quality, it cannot be conclusively assessed. Based on the images received, the source of the reported pain could not be determined. Clinic notes from an office visit on (b)(6) 2015 were later received indicating that the patient's vns was interrogated with patient in several different positions. Impedance ranged from 3050 to 3089 ohms. It was reported that the lead impedances have slowly increased over several months. Impedance was 2847 ohms in (b)(6) 2015, 2961 ohms in (b)(6) 2015, and 3089 ohms on (b)(6) 2015. Patient stated she has intermittent pain at the generator site which hurts randomly and with position changes. The pain does not only occur when device is stimulating. Patient was referred to surgeon to evaluate the vns site. Additional relevant information has not been received to date.

Event Description Patient underwent generator and lead replacement on (b)(6) 2015. High impedance was observed prior to surgery during diagnostic testing but no obvious lead fracture was observed. It was reported that the patient had an excessive scar tissue surrounding the electrodes. Product return is expected but has not been received to date.

Event Description Generator and lead were received for analysis on 12/01/2015. The reported fracture of lead and high impedance allegations were not verified within the returned lead portion. A portion of the lead (including the electrode array) was not returned for analysis; therefore an evaluation of the missing portion of lead cannot be made. Other than typical wear and explant related observations, no anomalies were identified in the returned lead portion. The reported allegation of ¿high impedance¿ was not verified during the generator analysis. Various electrical loads were attached to the pulse generator and results of diagnostic tests demonstrate that accurate resistance measurements were obtained in all instances. The septum was not cored, thus eliminating the possibility of a potential unintended electrical current path through body fluids. In the pa lab, the device output signal was monitored for more than 24-hrs, while the generator was placed in a simulated body temperature environment. Results showed no signs of variation in the pulse generator¿s output signal and demonstrated that the device provided the expected level of output current for the entire monitoring period. In addition, a comprehensive automated electrical evaluation showed that the pulse generator performed according to functional specifications. The battery, 2. 992 volts, shows an ifi=no condition. There were no performance or any other type of adverse conditions found with the pulse generator. Additional information was received that the patient was in clinic for a follow up visit on (b)(6) 2015 after the full revision surgery. The patient is still experiencing pain associated with stimulation. The patient reports that when the device is programmed off, the pain subsides. Diagnostics were performed and the impedance was within normal limits (2624ohms). When the wand was placed over the generator in order to run diagnostics and the patient stated that that it was painful. The patient is on rapid cycling and no programming changes were performed. When diagnostics were performed, the patient had no reaction or discomfort. The patient requested that the device be programmed off.

Model Number 302-20Event Date 10/06/2015Event Type Malfunction Event Description It was reported that vns system implanted in the patient was tested and system diagnostics returned high impedance with dcdc code 7 and neos no. X-rays were taken and sent to the manufacturer for review. The generator appears to be placed under the right arm in an abnormal arrangement. The filter feed-through wires appears to be intact. The insertion of the lead-pin connector could not be fully assessed due to the orientation of the generator in the x-rays and the quality of images, it appears to be not fully inserted. The electrodes appeared to be placed in abnormal arrangement, not in the neck. A strain-relief bend and a loop were not used. Only one tie-down was found holding the upper lead body. Part of the lead appeared to be behind the generator and could not be assessed. No clear lead breaks or sharp angles were found in the parts of the lead that could be assessed. It was reported by the physician that the device was not switched off yet. No known surgical interventions have occurred to date. No patient adverse events were reported to date.

Event Description Further information was received from the facility, indicating that the patient underwent full replacement surgery on (b)(6) 2016. The lead was replaced due to lead discontinuity and the generator was prophylactically replaced. Review of manufacturing records confirmed that both, the generator and the lead passed all functional tests prior to distribution. It was reported that the explanted devices will not be returned to the manufacturer as they were discarded. Therefore, no analysis results could be provided. No additional information was provided to date.

Model Number 302-20Device Problems Loss of Power; Battery Problem Event Date 12/23/2015Event Type Malfunction Event Description It was reported that high impedance was observed on a vns patient's system on (b)(6) 2015. The device was turned off for the safety of the patient. It was also reported that the patient underwent a generator replacement on (b)(6) 2015 due to battery depletion. It was reported that x-rays were taken but those have been not provided to the manufacturer for review to date. Review of manufacturing records confirmed that the device passed all functional tests prior to distribution. No further information has been provided to date.

Event Description The x-rays have been provided to the manufacturer for the assessment. Review of those x-rays indicated that the generator appears in the upper left chest in a normal placement. The filter feed-through wires seem to be intact. The lead connector pin seems to be fully inserted into the generator connector block. The electrodes appeared normally placed on the vagus nerve. The strain relief bend and loop could not be assessed due to poor quality of the pictures. It seems that two tie downs were used to secure the implanted lead. A part of the lead is behind the generator and could not be assessed. No sharp angles or lead breaks were visible. Based on the x-rays provided, the cause of the reported high lead impedance remains unknown at this time.

Event Date 02/04/2016Event Type Malfunction Event Description It was reported that high impedance (dcdc 7) was observed on vns patient's system. Normal mode and system mode diagnostics were run and high impedance were found (dcdc 7). It was reported that the device was then disabled. X-rays were taken and sent to the manufacturer for review. The generator appears in the upper left chest in a normal placement. The filter feed-through wires appeared to be intact. The lead connector pin is fully inserted into the generator connector block. The electrode appears to be placed in abnormal arrangement (the negative electrode appears to be placed distal to head) but this could not be confirmed due to poor quality of the image. It's unable to assess if the strain-relief bend and loop are presents. No tie-down was found holding the lead. A portion of lead behind the generator could not be assessed. No suspected lead break was found on the visible part of the lead. Further information was received from the physician, indicating that the patient's generator was implanted in 2014. It's unknown if any patient trauma or manipulation occurred that could be the cause of the suspected lead fracture. As reported by the parents to the physician, the patient's seizures were stable until (b)(6) 2016, without explanation. The last device checking in (b)(6) 2015 found that the parameters / settings were normal. During a clinic visit on (b)(6) 2016, high impedance was found. The device was then switched off that day. It was reported that lead revision is planned. No known surgical interventions have been performed to date.

Model Number 302-20Event Date 04/01/2016Event Type Malfunction Event Description It was reported that a patient had high impedance on a follow-up visit with the physician that occurred on (b)(6) 2016. The patient also reported not feeling stimulation and an increase in seizures. In (b)(6), the patient had experienced a hard fall while hiking and the increase in seizures and the change in perception of the stimulation occurred after the fall. The seizure rate increased from 2-3 per month to 9 seizures during the month of april, after the fall. X-rays were sent to manufacturer for review. Based on the images provided, the source of the reported high impedance could not be determined. There did not appear to be any obvious lead discontinuities in the portion of the lead that could be visualized; however, part of the lead was difficult to assess due to the quality of the images. The presence of a micro-fracture in the lead could not be ruled out. Review of the x-rays showed inadequate strain relief. The patient underwent full revision surgery on (b)(6) 2016. Post-op system diagnostics showed impedance values within normal limits. No additional relevant information has been provided to date.

Event Description The generator and lead were received for analysis. Analysis of the lead was completed on 06/17/2016. Note that the electrodes were not returned for analysis; therefore a complete evaluation could not be performed on the entire lead product. During the visual analysis what appeared to be pitting was observed on the connector pin surface. A definite cause for the pitting could not be determined based on the lead portion returned. The condition of the returned lead portion is consistent with that which typically exists following an explant procedure. No other obvious anomalies were noted. The setscrew marks found on the lead connector pin provide evidence that, at one point in time, a good mechanical and electrical connection was present. Continuity checks of the returned lead portion were performed, during the visual analysis, and no discontinuities were identified. Analysis of the generator was completed on 06/21/2016. Review of the ram/flash data downloaded from the pulse generator shows a possible indication of increased impedance; the ¿diagvinitialprechange¿ value of 2085 ohms, the ¿diagvinitialpostchange¿ value of 19121 ohms, and the time of change detection (b)(6) 2016. It is likely that the generator was tested with a test resistor after explant to confirm high impedance within the lead. A comprehensive automated electrical evaluation showed that the pulse generator performed according to functional specifications. There were no additional performance or any other type of adverse condition found with the pulse generator.

Model Number 302-20Event Date 04/21/2016Event Type Malfunction Event Description An international distributor reported that a physician observed high lead impedance during a regular vns device check on (b)(6) 2016. The device was turned off on that date and no patient manipulation or trauma was reported. Diagnostic data submitted for the patient's current and former device were submitted. All impedance readings are normal for both device up until (b)(6) 2016 when the high impedance (>=10,000 ohms) was observed. X-ray images provided to the manufacturer. Based on the images provided, no obvious source of the high impedance condition was identified. Although the images revealed no gross anomalies, due to image quality and a portion of the lead being behind the generator, the entire lead body could not be accurately assessed. The presence of a micro-fracture could not be ruled out. The generator placement appeared normal in the left axillary chest area. The lead pin appeared to be fully inserted into the pulse generator header but could not be fully assessed due to the angle of the pulse generator. The pulse generator feedthru wires appeared to be intact and the lead wires appeared to be intact at the connector pin. The electrode position appears to be low (inferior) but this appearance may be due to the patient's neck position at the time of x-ray.

Event Description The physician's elected to perform a lead replacement surgery on (b)(6) 2016. Following replacement of the lead the vns system functioned properly. An implant card was received indicating that the lead was explanted and replaced due to lead discontinuity. The lead was received by the manufacturer and is currently undergoing product analysis.

Event Description Product analysis revealed that the lead assembly was returned for analysis in 5 pieces. Three sets of setscrew marks were seen on the connector pin providing evidence that proper contact between the setscrew and the connector pin existed at least once. A coil break was identified in the positive coil. Scanning electron microscopy images of the positive coil show that pitting or electro-etching conditions have occurred at the break location. The outer silicone tubing has a compressed appearance at multiple locations. Other than the above mentioned observations, and typical wear and explant related observations, no other anomalies were identified in the returned lead portions.

Event Date 05/03/2016Event Type Malfunction Event Description It was reported that during a generator replacement surgery, high impedance was observed upon connection of the new implanted device to the existing lead. It was reported that the generator was replaced due to end of service. It was reported that x-rays will be taken and provided to the manufacturer for review. It was reported that lead revision is planned. No known surgical interventions have been performed to date.

Event Description X-rays were taken and provided to the manufacturer for review. The generator appears in the upper left chest in a normal placement. The feed-through wires seem to be intact. Due to the bad quality of the provided pictures, the placement of strain relief, the presence of tie downs, the integrity of the lead wires at the connector pin could not be assessed. The presence of any gross fractures or discontinuities or sharp angles in the lead and the connection between the connector pin within the connector block could also not be assessed due to the quality of the provided images. It could not be fully assessed whether part of the lead was behind the generator or not. No additional relevant information was provided to date.

Model Number 304-20Device Problem Adverse Event Without Identified Device or Use Problem Event Date 02/28/2019Event Type Injury Manufacturer Narrative Device evaluated by mfr?, code 81: device evaluation is not necessary as the extrusion is not related to the functionality or delivery of therapy of the device.

Event Description It was reported that a patient's lead wire was extruding from the neck site through the skin. An image of the site were received from the surgeon showing an open wound with a white spot showing. It was unclear what was seen due to the quality of the image. An update was received stating that there was no evidence of an infection externally, but the patient was started on antibiotics and was admitted to the hospital. The lead tie down was confirmed to be exposed and the surgeon planned to clip the lead " as close as he can" without opening the carotid sheath to prevent infection. Based on this update, it was likely that the white spot from the image was the exposed tie down. It was stated that the patient had an itchy rash on his face and neck that he would "obsessively" scratch. The doctor and caregivers believed this excessive scratching caused the extrusion. The rash was clarified to be a dermatology-diagnosed condition that was unrelated to vns. The lead was explanted. Antibiotics were provided, though the surgeon stated there was no evidence of an infection. No additional, relevant information was received to date.

Model Number 300-20Device Problem Fracture Event Date 01/15/2019Event Type Malfunction Event Description It was reported that high impedance was detected on the patient's generator and that the patient was sent for x-rays. The patient's generator was disabled due to the high impedance observed. It was reported that the patient's generator was checked multiple times using multiple programming systems and that the physician believed the cause of the high impedance to be a lead fracture. It was reported that there was no known trauma or manipulation that could have contributed to the high impedance and that the patient was very compliant with their vns. Ap and lateral neck and chest x-rays were received and reviewed. The generator was located in the patient's upper left chest per labeling. Based on the images provided, the connector pins could be visualized as fully inserted and the filter feed through wires appeared to be intact. Due to the quality of the images it was unable to assess whether the lead was routed in front of or behind the generator. No sharp angles or fractures were identified in the visible portions of the lead. The cause of the patient's reported high impedance could not be determined based on the images provided. However, the presence of a micro-fracture and/or lead discontinuity could not be ruled out. No known relevant surgical intervention has occurred to date. No further relevant information has been received to date.

Model Number 302-20Device Problem Fracture Event Date 01/28/2019Event Type Malfunction Event Description It was reported that the patient's device was showing high impedance. It was noted that in (b)(6) 2018, the patient's impedance was within normal limits. X-rays were received for review. Per the x-rays, the generator placement appeared to be normal in the left axillary chest area. The feed through wires appeared intact and the lead pin appeared to be fully inserted into the generator connector block. The lead was observed in the chest and neck. Due to the quality and scope of the images, the presence of the strain relief bend and loop per labeling could not be determined. No tie downs were present securing the lead as recommended per labeling. Part of the lead was behind the generator and could not be assessed. In the portions of the lead visible, no gross lead fractures or other anomalies were observed. No known surgery has occurred to date. No additional, relevant information was received to date.

Model Number 303-20Device Problem High impedance Event Date 02/06/2019Event Type Malfunction Event Description It was reported that the patient had high impedance detected on their generator. It was reported that the patient's impedance value was within normal limits "recently. " an x-ray image was received with the report; however the image could not be reviewed for proper pin insertion or possible lead fractures as it was a poor quality compressed image. No known relevant surgical intervention has occurred to date. No further relevant information has been received to date.

Model Number 302-20Device Problems High impedance; Low impedance Event Date 10/09/2018Event Type Malfunction Event Description An implant card was received which noted that high/low lead impedance was observed during the patient's vns generator replacement due to battery depletion. Lead impedance was also marked to be normal on the implant card. Ap neck x-rays of the patient were previously reviewed. The connector pin appeared to be fully inserted inside the connector block, and feedthru wires appeared intact. There appeared to be a portion of the lead wire located behind the generator which was unable to be assessed. No obvious gross lead discontinuities or sharp angles were observed in the visible portion of the lead. Due to the image quality and angles, the lead and generator could not be completely assessed. Note that the presence of a micro-fracture and/or a lead discontinuity could not be ruled out in the portion of the lead that is not visible in the provided images. No additional or relevant information has been received to date.

Model Number 304-20Event Date 07/15/2016Event Type Malfunction Event Description It was reported that a patient had low impedance found during system diagnostics on a follow-up visit. X-rays were taken and provided to the manufacturer for review. The x-rays were reviewed by the manufacturer. The lead appeared intact, the electrodes appeared to be aligned on the left vagus nerve. The condition of the feedthru wires, pin insertion, and connector pin could not be assessed due to the clarity of the provided x-ray images. The generator was also found to be placed abnormally high in the left chest, adjacent to the clavicle. No obvious cause for the reported low impedance was found through review of the x-rays. No further relevant information has been received to date. No surgical intervention has occurred to date.

Model Number 302-20Event Date 08/22/2016Event Type Malfunction Event Description It was reported that high impedance (dcdc 7) was observed on vns patient's system during a follow-up visit on (b)(6) 2016. It was reported that the physician does not believe the event is related to vns. It was reported that the patient was referred for x-rays. No patient adverse events were reported. Review of manufacturing records of the lead confirmed all quality tests were passed prior to distribution. No known surgical interventions have been performed to date. No additional relevant information has been received to date.

Event Description It was reported that the patient was refered for x-rays, copy provided to the manufacturer for review. No obvious cause of the high impedance could be identified due to poor quality of the images. The placement of the generator looks normal from the images. The filter feed-through wires appeared to be intact. The lead connector pin appeared to be fully inserted. The lead wires at the connector appear to be intact. Strain relief bend and loop cannot be assessed from the images. Portions of the lead appeared to be behind the generator and could not be fully assessed. No acute angles or clear lead break were found in the parts of the lead that could be assessed. No known surgical interventions have occurred to date.

Event Description The patient underwent a full replacement due to the high impedance. After the full replacement, the patient's impedance values were within normal limits. The explanted products were reportedly not available for product return after the replacement.

Model Number 302-20Device Problems Fluid Leak; Fracture Event Date 08/02/2016Event Type Malfunction Event Description It was reported that the patient¿s generator registered high lead impedance shortly after generator replacement surgery on (b)(6) 2016. The generator was reported to have been pulse enabled leading up to the high impedance reading. During the appointment, the patient looked to the left, and the impedance moved from approximately 10,000 ohms to the 6000s ohms range. Lead impedance was reportedly within normal limits at the conclusion of the replacement surgery. X-ray images were received and reviewed by the manufacturer. The generator was placed normally per labeling. Due to the angle of the generator and quality of the image, the insertion of the lead pin could not be fully assessed. The feedthru wires appeared to be intact. The lead electrodes appeared to be appropriately placed per labeling. There were no apparent sharp angles or gross fractures of the lead that could be seen in the portions of the lead that could be visualized. The lead appeared obscured by the generator based on the lead tract. However, it is uncertain if the lead is actually behind the generator. Based on the x-rays received, the cause for the high impedance could not be determined. There was no visual indication of damage to the generator or lead. Nonetheless, the presence of a micro-fracture in the lead could not be ruled out. Surgery to address the high impedance has not occurred to date. No additional pertinent information has been received to date.

Event Description It was reported that a high impedance flag continued to be observed on the patient¿s vns system. Multiple body positions were attempted with the same result. The patient¿s caregivers reportedly noted that they believed "something was wrong with [their] child's battery" in the summer of 2016 due to increased behaviors at school and home. The generator that was explanted in the previous generator replacement case underwent product analysis. When received, the internal data was downloaded from the pulse generator. Review of the data indicated that the generator had reached an end of service condition. Additionally, there was evidence of increased impedance during the use life of the generator. The suspect lead and paired generator were explanted. The explanted lead and generator were received by the manufacturer and are undergoing product analysis.

Event Description Product analysis was completed on the other returned generator. Visual examination showed only observations consistent with the explant process; no surface abnormalities were noted on this device. The device output signal was monitored for more than 24-hrs in a simulated body temperature environment. The pulse generator showed expected level of output currents and no signs of variation. Both interrogation and system diagnostic tests were performed. Various electrical loads were attached to the pulse generator and results of diagnostic tests demonstrate that accurate resistance measurements were obtained in all instances. A comprehensive automated electrical evaluation showed that the pulse generator performed according to functional specifications. The battery measured 2. 984 volts during functional testing and showed an ifi=no condition. The internal device data showed that 3. 159% of the battery had been consumed. The internal device data contained evidence of increased impedance during the implant life of the device. One day following the implant of the device, the generator registered a change of impedance from 5659 ohms to 13572. The extended impedance history also contained evidence of high impedance as early as the date of implant. There were no performance or any other type of adverse conditions found with the pulse generator. Product analysis was completed on the returned lead portions. Note that since a portion of the lead was not returned for analysis, an evaluation and resulting commentary cannot be made on that portion of the lead. Setscrew marks were seen on the connector pin, providing evidence that proper contact between the setscrew and the connector pin existed at least once. Inspection of the first portion of the returned lead showed the outer silicone tubing has an abraded opening approximately 9. 4-10cm from the boot. Inspection of the second portion of the returned lead showed the outer silicone tubing is abraded open at approximately 21-21. 3cm from the boot. The lead assembly has dried remnants of what appear to have once been body fluids inside the outer silicone tubing due to the abraded outer tube openings. Impedance measurements to identify potential discontinuities were performed, and showed no discontinuities within the returned lead portions. Other than the above mentioned observations and typical wear and explant related observations, no anomalies were identified in the returned lead portions.